Sift together salt, baking powder and flour. Alternately add sour milk and flour mixture to the
batter, mixing after each addition.

Beat egg whites until stiff. Fold egg whites and nuts into batter. Pour into a greased
9-by-13-inch cake pan and bake for 30 to 35 minutes.

Note: Few directions came with this recipe, so we added instructions. Instead of
sour milk, we used low-fat buttermilk. To sour milk, add 11/2 teaspoons white vinegar to the 11/2
cups of whole milk and let sit for 10 minutes.